Canon EOS-1D X Mark III EOS-1DX Mark III Advanced User Guide - Page 842

FE Microadjustment Caution Normally, this adjustment is not required. Perform this adjustment only if necessary. Note that performing this adjustment may prevent you from obtaining suitable flash exposure. You can fine-tune the standard flash exposure level. Effective if main subjects in autoflash shooting without flash exposure compensation usually seem underexposed or overexposed. OFF: Disable ON: Enable To access the adjustment screen, select [Enable], then press the < > button. Standard flash exposure can be adjusted in a range of ±1 stop, in 1/8-stop increments. Set on the positive side if main subjects tend to be underexposed and on the negative side if they tend to be overexposed. 842